The importance of the hydroxylated forms of vitamin D as regulators of calcium and phosphate metabolism in animals and humans is by now well recognized through many disclosures in the patent and general literature. Vitamin D.sub.3 is known to be hydroxylated in vivo to 25-hydroxyvitamin D.sub.3 and then to 1 alpha,25-dihydroxyvitamin D.sub.3, the latter being generally accepted as the active hormonal form of vitamin D.sub.3. Similarly, the very potent vitamin D.sub.2 metabolite, 1 alpha,25-dihydroxyvitamin D.sub.2 (1 alpha,25- (OH).sub.2 D.sub.2) is formed from vitamin D.sub.2 via 25-hydroxyvitamin D.sub.2 (25-OH-D.sub.2). Both of these hydroxylated vitamin D.sub.2 compounds have been isolated and identified (DeLuca et al, U.S. Pat. Nos. 3,585,221; 3,880,894) and syntheses relating to hydroxyvitamin D.sub.2 derivatives has also been reported (Sardina et al. Tet. Letters 24, 4477 (1983); DeLuca et al., U.S. Pat. No. 4,448,721; Yamada et al. Tet. Letters, 25, 3347 (1984); Baggiolini et al. U.S. Pat. No. 4,508,651; Morzycki et al. Journ. Org. Chem. 49, 2148 (1984)).